The collection, presentation, and interpretation of directional data measured from sedimentary structures and textures which were formed under flowing water, the wind, or moving ice. Ranging from the study of a single structure to data collected across a whole sedimentary basin, palaeocurrents can yield a hierarchy of information, from the local direction of flow which yielded a single ripple train, through the direction of migration of a bar or channel, to the movement of sediment through a river or deltaic network (see delta), and the regional pattern of sediment provenance and dispersal through a basin.